Safety device for railroad working



Oct. 9, 1934. J, BEHMER 1,975,762

SAFETY DEVICE FOR RAILROAD WORKING Filed Oct. 27, 1931 QA' TTOR/vgy jatenteci Oct. 9, 1934 STATE-S Perser @arms 1,915,12 SAFETY DEVICE Foa RAILROAD WQRKING Johannes Bhmer" Hamburg" Germani' i' Applicationoctober 27, mensen-a1 No. 571,411 In Germany May 13, 1931 2f' claims. (o1. 2465-249) The invention relates to safety devices for railroad-working, as described in the present speciiication and Lillustrated in the` accompanying drawing that forms part of the same.v

The invention-consists essentially in the novel features in safety devices for railroad working using magnetic needles, as pointed out in the vclaims for novelty following adescription in detail of a preferred form ofthe invention.

The objects of the invention are to insure greater safety and accuracy in safety devices for railroad working; to use Vthe directive forces of the rails or bar-magnets connected to them upon the magnetic needle in preference toithe earth? magnetism which proves too small #a directive force in View of the large masses of iron, especially in multipie-track lines; to obtain a high coefficient of safety in making or breaking the contact influencing the operating circuits; to produce a safety device which will not be infiuenced by the undesirable vibrations produced by the passage of trains; and generally to provide safety devices for railroad working, cheap to manufacture, easy to install and eiicient for the purposes set forth.

In the drawing, Figure 1 is a vertical cross sectional view of the safety device.

Figure 2 is a side elevational View of the partition Wall.

contact.

Like numerals of reference indicate corresponding parts in the various figures.

Referring to the drawing, the casing indicated g by the letter c is made of any suitable insulating material and has a central cavity, thel bottom of which is lined with a glass plate n having a central recess forming the lower bearing for the pivot o of the magnetic needle f.

The beam r diametrically bridging the casing c is recessed in the center to form a bearing for the upper end of the pivot o. The casing c has the glass cover z' suitably held in place by a flanged ring.

The wall e divides the cavity of the casing into two sections s and d, both of which are filled with mercury up to a certain level.

The wall c has the slot p just wide enough to allovv for the passage of the elbow y preferably 31 made of platinum Wire, and rigidly secured to the' needle f and terminating in a needle point h.

The level of the mercury in section s is such that the needle point clears it. In section d the level of the mercury is considerably higher than 1 in section s.

Figure 3 is a fragmentary detail of the magnet` The mercury contained in section d, owing to its v highsurf-ace tension, cannot escape through the slot p which as aforesaid is just wide enough to allow fcr the passage of the elbow g terminating in the neediepoint h adapted to pierce the surface of the mercury exposed by the slot, thereby facilitating easy penetration and insuring good electri cal contact.

v.The casing c sits on and is secured to a tray having a tubular extension t. v rlhe zinc or copper cap b forms withlsaid tray a protective watertight cover for the casing c.

The tubular extension is slidably mounted on the cylindrical stand cito which it is adjustably secured bythe setscrew Z.

The tray has a-threaded opening closed by a bushing m, through which pass the electr-ical wires la, one leading to section d and the other leading to section s.

The electrical circuit is as folloWs:-From the mercury contained in section s, to the mercury contained in section d through the pivot o, magnetic needle f and eblow g; the circuit being completed by the Wires lc.

Inl the operation, the magnetic polarity and the direction of the lines of nur; that the wheels and axles of the railroad vehicles assume when passing the particular point at which the device is to be located, being known, a magnetic field is established at that point in which the direction of the lines of force differs from the known neld. This may be accomplished by placing bar magnets in suitable positions adjacent to the track. The device is then placed in the magnetic field of the bar magnets and the magnetized bar in the manner of a compass adjusts itself to the lines of force. The casing is then oriented to place the contact arm in contact with or out of vcontact with the mercury as desired. The bar and the condition of the electrical circuit effected by the contact remains stable until some outside magnetic influence of suiiicient strength to affect the magnetic field is introduced. This outside influence is provided by the passage of the vehicle on the rails. The direction of the lines of force of the magnetic field of the vehicles and the bar magnets being made diierent, the passage of the vehicle will produce a deflection of the magnetic bar of the device which in moving will make or break the electrical circuit according to the setting.

It is easily understood that by reversing the bar magnets, the position of the magnetic needle could be changed and that consequently the closed circuit could be changed into an open one adapted to be closed by the elbow g entering the section d.

The above is an important feature of the invention as it permits the turning of a closed circuit installation into an open one, and vice versa, according to the various requirements of the installation and this almost instantaneously. The tubular extension and cylindrical stand construction allows easy adjustment of the device through the set screw Z, in that the device can be not only adjusted `vertically but also laterally by simply revolving the tubular extension. This feature combined with the reversability of the bar-magnets allows a very fine adjustment of the device to meet With all sorts of conditions and Y requirements.

The elbow construction of the contact point increases the contacting surface without decreasing the penetrability of the needle point.

Another feature of the invention consists in the close proximity of the needle point to the pivot, since relatively small torsional forces are to be considered.

I claim:

1. In a safety device for railroad working, a mercury contact device comprisingra compasslike magnetized bar pivoted to change direction in a horizontal plane, a Contact arm secured to said bar and extending downward therefrom and terminating in a needle point horizontally extending normal to said bar, a mercury container having an aperture in the side disposed to permit the entry of said contact arm, mercury in the container to aj level above said needle point, a second mercury container surrounding a pivot of said bar and mercury therein in contact with said pivot, said pivot being electrically connected to said contact arm, electrical connections from each quantity of mercury, a casing housing and supporting said bar and containers.

2. In a safety device for railroad working, a mercury contact device comprising a shallow mercury container of non-conducting material divided by a non-conducting barrier into two compartments, said barrier having an aperture connecting the two compartments, a magnetized bar horizontally mounted on a vertical shaft having upper and lower bearings, said lower bearingbeing located on the bottom of one of said compartments, said upper bearing having supporting means attached to said container, contact arm secured to said needle and extending downwards therefrom and terminating in a needle point extending substantially normal to said shaft, the locations of the shaft and the contact and the said hole in the barrier permitting the passage of the contact point and arm between the two `said compartments, a quantity of mercury in one compartment of suiiicient depth to provide electrical contact with said shaft, a quantity of mercury in the other compartment sufficient to extend above said aperture inthe barrier, a Water tight casing and cover enclosing device, a translating device having electrical connections to the Vseparate amounts of mercury,a post and socket support for said casing having securing means and adjustable vertically and rotatably, the device being placed in close proximity to the related track and oriented to make or break contact by the magnetic eifectof a passing vehicle on the magnetized bar.

JoHruvrLsv BHMER. 

